Establishment of in-house cDNA microarray for analysis of pathogenicity of Toxoplasma gondii infection and developing methods of diagnosis and therapy for toxoplasmosis

利用正常小鼠mRNA构建的15000个克隆组成的cDNA微阵列系统，对弓形虫感染诱导基因进行了分析，获得了β 2-微球蛋白、DMR、spot 14、teststeron和未知基因（暂命名为T.g.Res.X） 5个基因群。通过比较野生型BALB/c和野生型易感菌株C57BL/6以及野生型和IFN-_γ KO BALB/c小鼠的mRNA表达情况，发现T.g.Res.X在弓形虫感染的耐药菌株中表达。短句来源采用cDNA微阵列法测定野生型和IFN-γ敲除（KO）小鼠弓形虫热休克蛋白70 （T.g.HSP70）、慢殖子特异性基因T.g.HSP30/bag1和速殖子特异性基因SAG1 mrna，研究干扰素γ (IFN-_γ)对弓形虫慢殖子和速殖子阶段转化的影响。在野生型小鼠中，T.g.HSP30/bag1 mRNA在感染后持续表达3天，SAG1 mRNA在感染后持续表达9天。在IKO小鼠中，tt . hsp30 /bag1 mRNA的表达在PI后24小时急剧下降，SAG1 mRNA开始交替表达。tg.h sp70 mRNA快速表达7 ~ 8 d，小鼠在tg.h sp70 mRNA表达后立即死亡。因此，IFN-γ下调SAG1和T.g.HSP70 mRNA的表达。

By using our own made cDNA microarray system composed with around 15,000 clones established by using mRNA from normal mice, Toxoplasma gondii-infection-induced genes were analyzed Five gene groups, beta2-microblobulin, DMR, spot 14, teststeron, and an unknown (tentatively named as T.g.Res.X ) were picked up. T.g.Res.X was shown to express in a resistant strain to T.gondii infection when the mRNA expression was examined by comparing between a wild type resistant strain(BALB/c) and a wild type susceptible strain( C57BL/6), and also comparing between wild type and IFN-_γ KO BALB/c mice.Effects of interferon-gamma (IFN-_γ) on stage conversion between bradyzoites and tachyzoites of Toxoplasma gondii were investigated by measuring a virulent gene of T.gondii, heat shock protein 70 (T.g.HSP70), a bradyzoite-specifc gene, T.g.HSP30/bag1, and a tachyzoite-specific gene, SAG1 mRNAs with cDNA microarray method in wild type and IFN-γ knockout (KO) mice. In wild type mice, T.g.HSP30/bag1 mRNA expression continued for 3 days post infection(PI), while SAG1 mRNA expressed for 9 days PI. In IKO mice, T.g.HSP30/bag1 mRNA expression decreased drastically 24 hr post PI, and SAG1 mRNA began to express interchangeably. Then T.g.HSP70 mRNA expressed rapidly 7-8 days PI, and the mice died just after T.g.HSP70 mRNA expression. Thus, IFN-γ downregulates SAG1 and T.g.HSP70 mRNA expression.